Background. The purpose of this study was to analyse the changes of body composition and the effects of icodextrin dialysis solution over time on peritoneal dialysis (PD) in continuous ambulatory peritoneal dialysis (CAPD) patients. Methods. Among 183 incident patients, 75 patients finished a complete 36-month protocol. Clinical indices including daily glucose absorption and body composition, by bioelectrical impedance analysis (BIA), were measured in both groups (icodextrin group: 36 patients, non-icodextrin group: 39 patients) at the 1st (baseline), 12th, 24th and 36th months. Results. There were significant increases in body weight and fat mass during the 36 months after initiation of CAPD. It was found that 78% of 3 years of weight gain occurred during the first year and 88% of weight gain at the end of the first year was fat mass gain. The icodextrin group showed a significantly lower percent of fat mass during the first 36 months (P < 0.05) and also less changes in body weight, fat mass, percent (%) fat mass, visceral fat area and waist/hip ratio at 1, 2 and 3 years than the non-icodextrin group. There were no significant changes in total body water (TBW), extra cellular fluid (ECF), oedema index and lean body mass (LBM) through comparable daily and ultrafiltration volume (UFV) between the two groups during the initial 3 years. Factors associated with the higher percent of fat mass gain over time on peritoneal dialysis were age, diabetes, gender (female) and non-icodextrin group (all, P < 0.01, generalized estimating equation). Conclusion. The application of icodextrin solution may be a better option to alleviate excessive fat gain over time for patients on PD.